GB498477A - Method of and furnace for heating fluids - Google Patents

Abstract

A tubular furnace for heating fluids, e.g. hydrocarbon oils, comprises a rectangular heating and combustion zone defined by side walls 1 and end walls (not shown) and provided with an additional wall 9 against which the gases from burner ports 8 are directed in an upward direction so as to heat vertical <PICT:0498477/III/1> banks 13 of horizontal tubes 12 by radiant heat from the wall 9 and by reflected heat from the walls 1, the furnace gases then passing over a second bank of tubes 18 situated in a zone substantially vertically above the combustion zone and heated by convection from the residual heat of the furnace gases. In a modification, the wall 9 constitutes one of the outer walls 1 of the furnace, while in a further modification the furnace gases are directed upwardly over the inner surfaces of the furnace walls 1 so as to heat by radiation banks of tube arranged on opposite sides of the central wall 9. As shown in Fig. 1, the furnace is of the " double-end " fired type comprising two separate combustion zones 10, 11, and this construction may be utilized to subject two separate streams of oils to different heating conditions. Examples are given of different methods of connecting up the tube-banks 13 ... 18 in any desired sequence to obtain the most advantageous heating conditions for the particular oil under treatment. The convection tube-bank 18 is located in a zone 3 defined by side walls 4 connected by sloping walls 2 to the furnace wall 1 and is protected from radiant heat by a bank 17 of staggered tubes arranged wider apart than the tubes of the bank 18. The heated fluid then flows through banks 15, 16 arranged parallel to the sloping walls 2 before entering the banks 13, 14. Specification 328,064, [Class 32], is referred to.